Intraoperative transit time flow measurement predicts maturation of radiocephalic arteriovenous fistulas.

OBJECTIVE: The arteriovenous fistula (AVF) is the first choice for gaining vascular access for hemodialysis. However, 20% to 50% of AVFs fail within 4 months after creation. Although demographic risk factors have been described, there is little evidence on the intraoperative predictors of AVF maturation failure. The aim of this study was to assess the predictive value of intraoperative transit time flow measurements (TTFMs) on AVF maturation failure. METHODS: In this retrospective cohort study, intraoperative blood flow, measured using TTFM, was compared with AVF maturation after 6 weeks in 55 patients. Owing to its significantly higher prevalence and risk of nonmaturation, the radiocephalic AVF (RCAVF) was the main focus of this study. A recommended cutoff point for high vs low intraoperative blood flow was determined for RCAVFs, using a receiver operating characteristic curve. RESULTS: The average intraoperative blood flow in RCAVFs was 156 mL/min. Patients with an intraoperative blood flow equal or lower than the determined cutoff point of 160 mL/min, showed a 3.03 times increased risk of AVF maturation failure after 6 weeks, compared with patients with a higher intraoperative blood flow (P < .001). CONCLUSIONS: The intraoperative blood flow in RCAVFs measured by TTFM provides an adequate means of predicting AVF nonmaturation 6 weeks after surgery. For RCAVFs, a cutoff point for intraoperative blood flow of 160 mL/min is recommended for maximum sensitivity and specificity to predict AVF maturation failure after 6 weeks.

Discrimination of vascular aging using the arterial pulse spectrum and machine-learning analysis.

Aging contributes to the progression of vascular dysfunction and is a major nonreversible risk factor for cardiovascular disease. The aim of this study was to determine the effectiveness of using arterial pulse-wave measurements, frequency-domain pulse analysis, and machine-learning analysis in distinguishing vascular aging. Radial pulse signals were measured noninvasively for 3 min in 280 subjects aged 40-80 years. The cardio-ankle vascular index (CAVI) was used to evaluate the arterial stiffness of the subjects. Forty frequency-domain pulse indices were used as features, comprising amplitude proportion (Cn), coefficient of variation of Cn, phase angle (Pn), and standard deviation of Pn (n = 1-10). Multilayer perceptron and random forest with supervised learning were used to classify the data. The detected differences were more prominent in the subjects aged 40-50 years. Several indices differed significantly between the non-vascular-aging group (aged 40-50 years; CAVI <9) and the vascular-aging group (aged 70-80 years). Fivefold cross-validation revealed an excellent ability to discriminate the two groups (the accuracy was >80%, and the AUC was >0.8). For subjects aged 50-60 and 60-70 years, the detection accuracies of the two trained algorithms were around 80%, with AUCs of >0.73 for both, which indicated acceptable discrimination. The present method of frequency-domain analysis may improve the index reliability for further machine-learning analyses of the pulse waveform. The present noninvasive and objective methodology may be meaningful for developing a wearable-device system to reduce the threat of vascular dysfunction induced by vascular aging.

Coronary Collateral Flow Index Is Correlated With the Palmar Collateral Flow Index: Indicating Systemic Collateral Coherence in Individual Patients-Brief Report.

[Figure: see text].

Contemporary outcomes of a "snuffbox first" hemodialysis access approach in the United States.

OBJECTIVE: The Society for Vascular Surgery guidelines for permanent hemodialysis (HD) access creation recommend prioritizing the most distal possible autogenous access to minimize complications and preserve more proximal options. The "snuffbox" arteriovenous fistula (AVF) is the most distal radial artery-cephalic vein AVF. Despite the theoretical benefits of the snuffbox approach, recent trends have been toward upper arm access. Our study sought to investigate the feasibility of a snuffbox-first strategy for HD access in all anatomically appropriate candidates. METHODS: From January 2016 to August 2019, all patients with end-stage renal disease (ESRD) or pre-ESRD under consideration for HD access were evaluated for a snuffbox-first approach by a team of vascular surgeons and nephrologists at a single, urban academic medical center in the United States. Data were collected prospectively and supplemented by medical record review. A survival analysis was performed to evaluate primary unassisted and secondary patency and clinical and functional maturation. Patients were censored if they had received a kidney transplant or had died. Cox proportional hazards regression was used to determine the risk factors for prolonged clinical maturation and functional maturation. RESULTS: A total of 55 snuffbox AVFs were created. The median patient age was 60 years (interquartile range [IQR], 52-70 years), and 52.7% of the patients were men. The median follow-up was 369 days (IQR, 166-509 days). The median survival for primary unassisted patency was 90 days (95% confidence interval [CI], 79-111). Secondary patency at 1 year was 92.3% (95% CI, 85.3%-99.9%). The clinical maturation rate at 1 year was 83.7% (n = 55; 95% CI, 66.8%-91.9%), and the functional maturation rate at 1 year was 85.6% (n = 40; 95% CI, 63.3%-94.4%). Of the patients who were pre-ESRD at AVF creation and had initiated HD during the study period, 87.5% had successfully received incident HD with their snuffbox AVF. Twenty-four patients were receiving HD via a catheter at snuffbox creation. Of those patients, the functional maturation rate at 1 year was 82.5% (95% CI, 44.8%-94.4%). The patients had undergone a median of two interventions (IQR, zero to seven interventions) in the first year. Of these, 46.9% were percutaneous angioplasty and 31.2% were side-branch ligation. Diabetes was associated with slower AVF clinical maturation (multivariate hazard ratio, 0.35; 95% CI, 0.15-0.82; P = .016). A larger artery diameter was associated with earlier AVF clinical maturation (multivariate hazard ratio, 6.64; 95% CI, 2.11-20.9). CONCLUSIONS: A snuffbox-first approach to HD access is a viable option for distal access creation in a cohort of patients requiring HD in the United States. Subsequent ancillary interventions to facilitate access maturation were required for most patients.

Salvage of a Radiocephalic Arteriovenous Hemodialysis Fistula by Percutaneous Angioplasty to Increase Retrograde Flow from the Palmar Arch in Patients with an Occluded Radial Artery.

This brief report presents 12 patients who underwent percutaneous transluminal angioplasty (PTA) to increase the retrograde blood flow from the palmar arch. All the patients had radiocephalic arteriovenous fistulas with occluded feeding arteries. The technical success rate was 100%. Three patients (25.0%) underwent surgical repair for restenosis, 2 patients (16.6%) underwent surgical repair for other reasons, 5 patients (41.8%) underwent repeated PTAs for restenosis, and 2 patients (16.6%) had no further treatment. The target lesion primary patency rates at 6, 12, 36, and 60 months were 90.9%, 54.5%, 36.4%, and 18.2%, respectively.

Recanalization of the occluded radial artery via distal transradial access in the anatomic snuffbox.

BACKGROUND: Radial artery occlusion is a common complication after coronary angiography and percutaneous coronary intervention via the transradial access. In recent years, coronary angiography and percutaneous coronary intervention via the distal transradial access has gradually emerged, but recanalization of the occluded radial artery through the distal transradial access has rarely been reported. CASE PRESENTATION: A 67-year-old female with arterial hypertension and diabetes mellitus was admitted to the hospital due to chest pain for three hours. She was diagnosed with acute myocardial infarction. After admission, the patient successfully underwent emergency coronary angiography and percutaneous coronary intervention through the right transradial access. Radial artery occlusion was found after the operation, and recanalization was successfully performed through the right distal transradial access before discharge. Immediately after the operation and one month later, vascular ultrasonography showed that the antegrade flow was normal. CONCLUSIONS: This report presents a case of radial artery occlusion after emergency coronary angiography and percutaneous coronary intervention in which recanalization was successfully performed through the right distal transradial access. This case demonstrates that recanalization of a radial artery occlusion via the distal transradial access is safe and feasible.

Real-World Usage of the WavelinQ EndoAVF System.

BACKGROUND: Dependent on existing deep to superficial perforating venous branches, the WavelinQ EndoAVF System is a novel technique used to create an arteriovenous fistula (AVF) between ulnar or radial veins and concomitant arteries for dialysis access. We sought to examine a single center's success rates and short-term follow-up using this device. METHODS: All consecutive patients undergoing placement of a WavelinQ AVF from October 2018 to July 2019 were included. Preoperative/intraoperative variables including demographics, preoperative/postoperative duplex ultrasonography, success rate of procedure, and subsequent endovascular/surgical procedures were obtained. Descriptive statistics and comparison of groups requiring subsequent intervention were performed. RESULTS: Thirty-five patients underwent placement of the WavelinQ AVF, with 32 (91%) patients having at least one documented follow-up. These patients were predominantly male (23/32, 72%) with an average age of 60.2 and 23 of 32 (72%) patients were on dialysis. Initial fistula creation success rate was 100%. Average procedural length was 120 min, fluoroscopy time 9.6 min, and contrast usage 52.2 mL. Eight of 32 (25%) patients had perioperative complications (3 hematomas, 3 contrast extravasations, 1 resolved vessel spasm all resolving spontaneously, and 1 pseudoaneurysm requiring surgical repair). Thirteen of 32 (41%) patients underwent subsequent endovascular interventions to assist with maturation [9/32 (28%) branch coiling, 5/32 (16%) angioplasty/stenting, and 3/32 (9%) access thrombectomy] and 4 of 32 (13%) patients required subsequent surgical interventions (1 pseudoaneurysm repair, 1 revision of fistula, and 2 definitive AVF creation in thrombosed grafts). The majority of accesses (30/32, 94%) were ulnar-ulnar fistulas and overall patency at average follow-up of 73 days was 88% (28/32) with average brachial artery inflow volume of 1,078 cc/min and average cephalic vein (18/32) outflow volume of 447 cc/min. Eleven of 23 (48%) patients on dialysis were successfully using the EndoAVF at follow-up. CONCLUSIONS: The WavelinQ AVF system has a high initial procedural success rate, although a significant portion of patients require subsequent endovascular procedures to aid in maturation. Further work on determining factors predictive of need for reintervention is necessary.

Statins Protect against Thrombosis of Cannulated Radiocephalic Fistulas in Diabetic Patients.

BACKGROUND: Radiocephalic arteriovenous fistula (RCAVF) creation is the preferred first line hemodialysis access procedure. Analysis of diabetic rat arteriovenous fistula model indicates improved vascular function with HMG-CoA-Reductase Inhibitor (statin) use. We predict similar outcomes in diabetic patients undergoing primary RCAVF placement. METHODS: A Veterans Administration Hospital dialysis access database over a 15-year period was queried identifying all RCAVF placements in diabetic patients. Patients were stratified into statin medication usage or not at RCAVF creation. Outcomes examined include rate of successful cannulation, functional patency duration, interventions per access, and rates of access thrombosis. Thrombosis-free survival of cannulated RCAVFs were compared using Kaplan-Meier method with log-rank analysis followed by univariate, stepwise logistic regression and ROC curve analysis. RESULTS: Total number of 123 RCAVF cases were performed in 122 diabetic male patients. At the time of RCAVF placement, 92 cases were performed on patients that were taking statin medication and 31 cases were performed on patients that were not taking statin medication. There was no difference in terms of rate of successful cannulation, functional patency duration, and number of interventions per access between the statin and non-statin groups. However, rate of RCAVF thrombosis once accessed was significantly lower in the statin group compared to the non-statin group (P = 0.0005). Kaplan-Meier survival curve for each group were compared using log-rank test to reveal that diabetic patients who were on statin therapy at the time of operation had significantly higher access survival over time against thrombosis once it was cannulated for dialysis treatment compared to those who were not on statin therapy (P = 0.0003). Univariate, stepwise logistic regression model indicated statin use as the only significant factor associated with lack of thrombosis (P = 0.05). CONCLUSIONS: Statins appear to have protective effects against RCAVF thrombosis as predicted in animal models for diabetic patients undergoing primary RCAVF placements. There were similar functional outcomes in terms of rate of successful cannulation, functional patency duration, and number of interventions per access. These data should encourage further investigation of statins and their role in hemodialysis access.

Blood flow changes in the forearm arteries after ultrasound-guided costoclavicular brachial plexus blocks: a prospective observational study.

BACKGROUND: An increase in blood flow in the forearm arteries has been reported after brachial plexus block (BPB). However, few studies have quantitatively analysed the blood flow of the forearm arteries after BPB or have studied only partial haemodynamic parameters. The purpose of the present study was to comprehensively assess blood flow changes in the distal radial artery (RA) and ulnar artery (UA) after BPB performed via a new costoclavicular space (CCS) approach using colour Doppler ultrasound. METHODS: Thirty patients who underwent amputated finger replantation and received ultrasound-guided costoclavicular BPB were included in the study. The haemodynamic parameters of the RA and UA were recorded before the block and 10 min, 20 min, and 30 min after the block using colour Doppler ultrasound to determine the peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (Vmean), pulsatility index (PI), resistance index (RI) and area. The volumetric flow rate (VFR) was calculated using the formula Q = area×Vmean. The aforementioned parameters were compared not only before and after the BPB but also between the RA and UA. RESULTS: Compared with those of the respective baselines, there was a significant increase in the PSV, EDV, Vmean, area, and VFR and a significant decrease in the PI and RI of the RA and UA 10 min, 20 min, and 30 min post-block. The increase 30 min post-block in EDV (258.68 % in the RA, 279.63 % in the UA) was the most notable, followed by that in the Vmean (183.36 % in the RA, 235.24 % in the UA), and the PSV (139.11 % in the RA, 153.15 % in the UA) changed minimally. The Vmean and VFR of the RA were significantly greater than those of the UA before the BPB; however, there was no significant difference in the VFR between the RA and UA after the BPB. CONCLUSIONS: A costoclavicular BPB can increase blood flow in the forearm arteries. The RA had a higher volumetric flow rate than the UA before the BPB; however, the potential blood supply capacity of the UA was similar to that of the RA after a BPB. TRIAL REGISTRATION: This study was registered at the Chinese Clinical Trial Registry (http://www.chictr.org.cn/searchproj.aspx, clinical trial number: ChiCTR 1900023796, date of registration: June 12, 2019).

Comparison of one-year patency rates of end-to-side and side-to-side anastomosis technique in proximal forearm region radial-cephalic fistulas.

OBJECTIVES: In this study, the effects of anastomosis techniques on the results of patients with autogenous radial-cephalic proximal forearm fistula were investigated. METHODS: Patients who underwent radial-cephalic proximal forearm fistula surgery (arteriovenous fistula) between April 2015 and August 2017 at the Department of Cardiovascular Surgery of Ordu University were compared retrospectively in terms of the results of anastomosis techniques. The study included 131 patients who had arteriovenous fistulas created by side-to-side and end-to-side anastomosis technique. RESULTS: There was no significant difference in demographic data, comorbidities, radial artery, and cephalic vein diameters in patients undergoing radial-cephalic proximal forearm fistula surgery. However, it was observed that fistula maturation was earlier in the group with end-to-side anastomosis technique, and the one-year patency rates were higher in the group with side-to-side anastomosis technique. CONCLUSION: In Arteriovenous fistulas created in the proximal forearm region, the one-year patency rate of the side-to-side anastomosis technique was higher, while the maturation of the end-to-side technique observed earlier.

Endovascular management of critical hand ischemia by 'palmar arch loop' technique.

INTRODUCTION: Critical hand ischemia with advancing gangrene of digits requires urgent intervention to salvage as much tissue as possible. The purpose of this study was to evaluate the efficacy of "palmar arch loop" technique for endovascular management of critical hand ischemia by establishing inline flow to the palmar arch via both radial artery and ulnar artery, in patients with failed antegrade recanalization. To the best of our knowledge, this is the first case series evaluating the efficacy of "palmar arch loop" technique, with retrograde percutaneous transluminal angioplasty of the involved radial artery and/or ulnar artery. MATERIAL AND METHODS: We retrospectively investigated 10 patients (60% female; mean age 42 ± 18 years; mean time of presentation post-acute event 24 ± 11 days) with critical hand ischemia undergoing endovascular intervention using "palmar arch loop" technique at a single center in northern India between April 2017 and March 2019. All patients were followed up at regular intervals (weekly for a month, fortnightly for 3 months, and then at 6 and 12 months) with clinical assessment and SpO2 measurement. Study end points were technical success rate, hand healing, and primary patency rate at one year. RESULTS: Causes for critical hand ischemia were iatrogenic injuries due to inadvertent intra-arterial injection in 50% (n = 5) and thromboembolic events in 50% patients (n = 5). Vessels involved were: both radial artery and ulnar artery along with the PA in 50%; radial artery and palmar arch in 30%; ulnar artery and palmar arch in 20%. All of them had total occlusion of the involved vessel (>2/3rd of total length) with occlusion/diffuse disease of palmar arch as well; 70% technical success rate was achieved ensuring inflow to palmar arch via both the arteries with improved flow distally to the common and proper digital arteries. Retrograde percutaneous transluminal angioplasty of radial artery in 50% (n = 5) and ulnar artery in 20% (n = 2) was done successfully by looping the guidewire across the palmar arch; 90% showed subjective improvement in pain with healing of the lesions and/or formation of clear line of demarcation with reversal of pregangrenous changes proximally. Out of the eight patients with gangrene of fingers, three underwent minor amputation of the gangrenous digits and five underwent auto-amputation of the gangrenous tissue with complete healing of the stump. Primary patency rate was 85.7% at one year. There was no access site-related complication or mortality in the follow-up period. CONCLUSIONS: Endovascular management of critical hand ischemia by "palmar arch loop" technique is an efficient technique to deal with occluded forearm vessels, particularly when antegrade recanalization fails. This technique, with good technical success and patency rates, is potentially a unique tool in the endovascular armamentarium for salvaging hand.

Effect of wrist dorsiflexion on ultrasound-guided radial artery catheterisation using dynamic needle tip positioning technique in adult patients: a randomised controlled clinical trial.

BACKGROUND: It is generally recommended to keep the wrist joint mildly dorsiflexed during radial artery catheterisation. However, wrist dorsiflexion might decrease the success rate of radial artery catheterisation with dynamic needle tip positioning technique. Therefore, we assessed the success rates of two groups with or without wrist dorsiflexion by 5 cm wrist elevation in adult patients. METHODS: This randomised controlled clinical trial was performed between March and December 2018 in the First Affiliated Hospital of Shantou University Medical College, China. We recruited 120 adult patients undergoing major surgical procedures and randomly allocated them into two groups: dorsiflexion group (group D) and neutral group (group N). The primary outcome was first-attempt success rates of two groups. Secondary outcomes were overall success rates within 5 min; numbers of insertion and cannulation attempts; overall catheterisation time; duration of localisation, insertion and cannulation; and complication rates of catheterisation. RESULTS: First-attempt success rate was 88.3% in group D and 81.7% in group N (p=0.444). The overall success rate within 5 min was 93.3% in group D compared with 90.0% in group N (p=0.743). Numbers of insertion and cannulation attempts, overall catheterisation time, duration of localisation and insertion, and complication rates did not show a significant difference between the two groups. Cannulation time was longer in group N (35.68 s) than that in group D (26.19 s; p<0.05). CONCLUSION: Wrist dorsiflexion may not be a necessity for ultrasound-guided radial artery catheterisation using dynamic needle tip positioning technique in adult patients. TRIAL REGISTRATION NUMBER: ChiCTR1800015262.

First, do no harm: bilateral radial artery occlusion in a COVID-19 patient.

OBJECTIVE: Objective of this case report is to draw attention to a less known thrombotic complication associated with COVID-19, i.e., thrombosis of both radial arteries, with possible (long-term) consequences. THE CASE: In our COVID-19 ICU a 49-year-old male patient was admitted, with past medical history of obesity, smoking and diabetes, but no reported atherosclerotic complications. The patient had been admitted with severe hypoxemia and multiple pulmonary emboli were CT-confirmed. ICU-treatment included mechanical ventilation and therapeutic anticoagulation. Preparing the insertion of a new radial artery catheter for invasive blood pressure measurement and blood sampling, we detected that both radial arteries were non-pulsating and occluded: (a) Sonography showed the typical anatomical localization of both radial and ulnar arteries. However, Doppler-derived flow-signals could only be obtained from the ulnar arteries. (b) To test collateral arterial supply of the hand, a pulse-oximeter was placed on the index finger. Thereafter, the ulnar artery at the wrist was compressed. This compression caused an immediate loss of the finger's pulse-oximetry perfusion signal. The effect was reversible upon release of the ulnar artery. (c) To test for collateral perfusion undetectable by pulse-oximetry, we measured regional oxygen saturation (rSO2) of the thenar muscle by near-infrared spectroscopy (NIRS). Confirming our findings above, ulnar arterial compression demonstrated that thenar rSO2 was dependent on ulnar artery flow. The described development of bilateral radial artery occlusion in a relatively young and therapeutically anticoagulated patient with no history of atherosclerosis was unexpected. CONCLUSIONS: Since COVID-19 patients are at increased risk for arterial occlusion, it appears advisable to meticulously check for adequacy of collateral (hand-) perfusion, avoiding the harm of hand ischemia if interventions (e.g., catheterizations) at the radial or ulnar artery are intended.

Influence of artery and vein diameters on autogenous arteriovenous access patency.

OBJECTIVE: Previous investigations have suggested that a minimum venous outflow diameter (MVOD) and perianastomotic arterial diameter are associated with successful autogenous arteriovenous maturation and patency. The goal of this study was to determine anatomic and clinical variables that may influence access patency to guide optimal autogenous access configuration selection. METHODS: Accesses created from 2010 to 2016 were analyzed from data entered into a prospective database. Preprocedure duplex ultrasound mapping data of artery and tourniquet-derived vein diameters and demographic and clinical variables were collected. Survival-based cut point analysis was used to determine anatomic parameters most predictive of access failure. Kaplan-Meier and Cox proportional hazards analyses were used to assess patencies and maturation and to identify independent predictors of access failure. RESULTS: A total of 356 first-time autogenous accesses were created (median follow-up, 20 months; range, 0-73 months). Of these, 202 (56.7%) were radiocephalic and 154 (43.3%) were brachiocephalic. Maturation failure at end of follow-up for arteriovenous accesses was 26% ± 3% for radiocephalic accesses and 15% ± 3% for brachiocephalic accesses (P < .001). For radiocephalic accesses, MVOD <3.0 mm and radial artery diameter <2.1 mm independently predicted access maturation failure (MVOD <3.0 mm: hazard ratio [HR], 2.62 [95% confidence interval (CI), 1.27-5.39; P = .009]; radial artery diameter <2.1 mm: HR, 2.20 [95% CI, 1.20-4.05; P = .011]) and secondary patency loss (MVOD <3.0 mm: HR, 2.21 [95% CI, 1.24-3.96; P = .007]; radial artery diameter <2.1 mm: HR, 2.11 [95% CI, 1.26-3.63; P = .004]). A combination of radial artery diameter <2.1 mm and MVOD <3.0 mm most strongly predicted maturation failure (HR, 4.24; 95% CI, 1.71-10.49; P = .002) and loss of secondary patency (HR, 4.03; 95% CI, 1.88-8.64; P < .001). Only diabetes mellitus (HR, 2.24; P = .012) predicted secondary patency loss. For brachiocephalic accesses, MVOD <3.4 mm (HR, 2.12; 95% CI, 1.02-4.46; P = .043) was found to independently predict secondary patency loss in addition to previous ipsilateral (HR, 2.37; P = .038) and bilateral (HR, 4.00; P = .015) tunneled hemodialysis catheters. Brachial artery diameter was not associated with either access maturation or patency. CONCLUSIONS: Artery and tourniquet-derived vein diameters independently predict radiocephalic access patency and functional outcomes. A combination of a radial artery diameter <2.1 mm and MVOD <3.0 mm best predicts maturation failure and patency loss for radiocephalic access. MVOD <3.4 mm was associated with increased loss of brachiocephalic access secondary patency, but MVOD was not associated with maturation.

Bypass surgery in a mangled forearm using an intramedullary tunnel through the radius.

Critical ischemia in the upper extremity is rare. A surgical bypass is thought to be the superior treatment option. We describe a rare case where regular tunneling options of the bypass were not available and an intramedullary tunnel was used.

Procedural and clinical performance of dual- versus single-catheter strategy for transradial coronary angiography: A meta-analysis of randomized trials.

OBJECTIVES: We sought to compare the procedural and clinical performance of dual- versus single-catheter strategy for transradial coronary angiography. BACKGROUND: The radial artery (RA) is recommended as the vascular access of choice in patients undergoing coronary angiography and intervention. The procedural and clinical performance of dual- versus single-catheter strategy in patients undergoing transradial coronary angiography remains a matter of debate. METHODS: This is a study-level meta-analysis of randomized trials. The primary outcome was procedure time. The main secondary outcome was fluoroscopy time. Other outcomes of interest were contrast volume, crossover to other catheter strategy and RA spasm. RESULTS: A total of 2,062 patients (978 randomly assigned to dual-catheter and 1,084 to single-catheter strategy) included in seven trials were available for the quantitative synthesis. A dual-catheter strategy was associated with procedure time (standardized mean difference [95% confidence intervals (CI)], 0.55 [-0.69, 1.78]; p = .32), fluoroscopy time (-0.36 [-2.39, 1.67]; p = .68) and contrast volume (-0.93 [-3.79, 1.94]; p = .44) comparable to a single-catheter strategy. The risk for crossover was lower (risk ratio [95% CI], 0.14 [0.03, 0.70]; p = .025) while the risk for RA spasm was higher (1.81 [1.54, 2.12]; p < .001) among patients assigned to dual- versus single-catheter strategy. CONCLUSIONS: This meta-analysis provides evidence for a comparable procedural performance of either dual- or single-catheter strategy for transradial coronary angiography. The fewer crossovers with dual-catheter strategy occur at the expense of more frequent radial artery spasm.

The "lend a hand" external bypass technique: External radial to femoral bypass for antegrade perfusion of an ischemic limb with occlusive large bore sheath - A novel and favorable approach.

An occlusive large bore sheath is a frequently encountered situation in cases of cardiogenic shock (CS) requiring mechanical circulatory support (MCS). Resultant acute limb ischemia could be a catastrophic complication which significantly affects the prognosis of an already sick patient population. A novel, yet simple, technique using the radial artery, instead of the ipsilateral or contralateral common femoral artery (CFA), as a donor vessel of an external bypass which provides antegrade perfusion to a limb with an occlusive large bore sheath is hereby described. Radial access (RA) has been shown to improve mortality in acute coronary syndrome; however, it is sometimes avoided by some operators in CS cases due to the possible appropriate need for MCS. This technique offers a substitution of a second CFA access for a RA in order to provide adequate ipsilateral limb perfusion. Hence, one can start a CS case with a default RA and perform peripheral angiography after diagnostic cardiac catheterization. If the peripheral vasculature is inappropriate for MCS, the patient would have already benefited from the mortality advantage of RA. If obstructive PAD is absent, then an occlusive Impella sheath can be placed in a CFA after antegrade ipsilateral superficial femoral artery (SFA) access is obtained for an external radial to femoral bypass, while the PCI is performed through the Impella sheath according to the single access PCI technique. Finally, the advantages and disadvantages of this new approach are described and compared with each of the traditionally known external and internal femoral bypass techniques.

Slender versus conventional approach reduces post-procedural upper extremity dysfunction after transradial coronary procedures.

AIMS: We compared the incidence of post-procedural radial artery occlusion (RAO) and upper extremity dysfunction (UED), in patients undergoing conventional versus slender transradial (TRA) coronary procedures. METHODS AND RESULTS: UED was assessed by the QuickDASH, before conventional (i.e., ≥6F) and slender (i.e., "virtual" 3F to 5F) procedures, after 2 weeks and 2 months. RAO was assessed by Duplex in patients with an abnormal reversed Barbeau test (RBT). A total of 212 patients were included, UED after 2 weeks was 12%, and after 2 months 7% (p = <.001). RAO occurred in 3%. Multivariate analysis showed an OR of 0.26 (CI0.08-0.84) for UED at 2 weeks (p = .03) in favor of slender TRA. In patients with RAO, UED did not improve at 2 months (2/5, 40%, p = .046). CONCLUSIONS: The occurrence of UED after TRA procedures is temporary except for patients with RAO. Slender TRA seems able to reduce short term UED.

SCAI expert consensus statement update on best practices for transradial angiography and intervention.

Transradial angiography and intervention continues to become increasingly common as an access site for coronary procedures. Since the first "Best Practices" paper in 2013, ongoing trials have shed further light onto the safest and most efficient methods to perform these procedures. Specifically, this document comments on the use of ultrasound to facilitate radial access, the role of ulnar artery access, the utility of non-invasive testing of collateral flow, strategies to prevent radial artery occlusion, radial access for primary PCI and topics that require further study.

Diagnosis and Treatment of Nonmaturing Fistulae for Hemodialysis Access via Transradial Approach: A Case-Control Study.

PURPOSE: To compare outcomes of transradial access for endovascular treatment of nonmaturing hemodialysis fistulae compared to brachial arteriography followed by unidirectional or bidirectional fistula access for intervention. MATERIALS AND METHODS: In this institutional review board-approved, retrospective, case-control study, 56 consecutive patients with nonmaturing arteriovenous fistulae underwent percutaneous intervention between 2015 and 2018. The transradial group (n = 28) underwent radial artery access for diagnostic fistulography and intervention. The control group (n = 28) underwent retrograde brachial artery access for fistulography followed by unidirectional/bidirectional fistula access for intervention. Both groups had similar demographics, fistula characteristics, and stenosis locations. RESULTS: Fewer punctures were required in the transradial group compared to controls (1.2 vs 2.4, P < .0001), and procedure time was shorter (64.9 vs 91.3 minutes, P = .0016). Anatomic, technical, and clinical success rates trended higher in the transradial group compared to controls (93% vs 86%, 96% vs 89%, and 82% vs 64%, respectively). Nonmaturation resulting in fistula abandonment was lower in the transradial group (3.7% vs 25%, P = .025). Primary unassisted patency at 3, 6, and 12 months was 77.1% ± 8.2%, 73.1% ± 8.7%, and 53.3% ± 10.6% in the transradial group, respectively, and 63.0% ± 9.3%, 55.6% ± 9.6%, and 48.1% ± 9.6% in the control group, respectively (P = .76). Primary assisted patency at 12 months was 92.3% ± 5.3% in the transradial group compared to 61.8% ± 9.6% at 12 months in the control group (P = .021). No major complications occurred. Minor complications were lower in the transradial group than in the control group (14% vs 39%, P = .068). CONCLUSIONS: Treatment of nonmaturing fistulae via a transradial approach was safe, improved midterm patency, and was associated with lower rates of fistula abandonment.